The value of single-photon emission computed tomography combined with computed tomography imaging in ¹²³I-Metaiodobenzylguanidine scintigraphy in children with neuroblastoma

The value of single-photon emission computed tomography combined with computed tomography imaging in ¹²³I-Metaiodobenzylguanidine scintigraphy in children with neuroblastomaWhole body scintigraphy with ¹²³I-Metaiodobenzylguanidine (¹²³I-MIBG) is an important imaging modality for evaluation of patients with neuroblastoma (NB). As the intrinsic nuclear scintigraphic characteristics, the assessment of conventional planar ¹²³I-MIBG images presents some difficulties. The limited resolution of planar images can induce false-negative results for small lesions, whereas the presence of physiologic MIBG uptake is not always easily differentiable from pathologic uptake and can induce false-positive results. Single-photon emission computed tomography combined with computed tomography (SPECT/ CT) hybrid imaging technique, allowing the direct fusion of morphologic and functional information, has been suggested to be more accurate. However, SPECT/CT imaging renders slightly more radiation to patients from CT portion of the study and is time consuming. The aim of our study was to investigate how much SPECT/CT can have additional diagnostic value over planar imaging in NB patients at initial staging. The study was approved by the Independent Ethics Committee and the Scientific Council of the D. Rogachev NMRCPHOI. A total of 251 SPECT/CT scans following by planar ¹²³I-MIBG imaging scans performed in 251 patients with NB were retrospectively analyzed. In 72.1% of the studies, the whole-body planar images and SPECT/CT images showed the same result. In 27.9% of studies, however, SPECT/CT images provided additional very important information. In our study, the diagnosis reached by planar imaging was revised or specified by SPECT/CT in 70 of the 251 patients and was clinically significant.

Positron Emission Computed Tomography Imaging of Synaptic Vesicle Glycoprotein 2A in Alzheimer’s Disease

Alzheimer’s disease (AD) is the most common neurodegenerative disorder seen in age-dependent dementia. There is currently no effective treatment for AD, which may be attributed in part to lack of a clear underlying mechanism. Early diagnosis of AD is of great significance to control the development of the disease. Synaptic loss is an important pathology in the early stage of AD, therefore the measurement of synaptic density using molecular imaging technology may be an effective way to early diagnosis of AD. Synaptic vesicle glycoprotein 2A (SV2A) is located in the presynaptic vesicle membrane of virtually all synapses. SV2A Positron Emission Computed Tomography (PET) could provide a way to measure synaptic density quantitatively in living humans and to track changes in synaptic density in AD. In view of the fact that synaptic loss is the pathology of both epilepsy and AD, this review summarizes the potential role of SV2A in the pathogenesis of AD, and suggests that SV2A should be used as an important target molecule of PET imaging agent for the early diagnosis of AD.

TECHNETIUM-99M MIBI GATED MYOCARDIAL PERFUSION SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY IMAGING – VALIDATION OF STRESS ONLY PROTOCOL

Objective: To validate ‘stress only’ protocol against ‘rest stress protocol in normal and essentially normal cases undergoing Tc99m MIBI gated myocardial perfusion Single Photon Emission Computed Tomography imaging. Study Design: A retrospective observational study. Place and Duration of Study: Department of Nuclear Cardiology, Armed Forces Institute of Cardiology/National Institute of Heart Disease, Rawalpindi, Pakistan, from Jul to Sep 2019. Methodology: 136 cases were included. Patients underwent Tc-99m gated Single Photon Emission Computed Tomography MPI using a single day, rest/stress protocol. The rest study was performed first with 8-10 mCi Tc-99m MIBI followed by stress study, 3 hours later with 3 times the rest dose. The most common stress technique was pharmacological stress and bicycle ergometer exercise with 0.14 mg/kg/min adenosine infusion. Few patients underwent physical stress using Bruce protocol, achieving a minimum of 85% of the target heart rate. Mages–stress followed by rest–were evaluated by two experienced nuclear cardiologists (blinded to the MPI reports) and interpreted as ‘normal’ or ‘essentially normal’. Results: Evaluation of stress-only and rest-stress Single Photon Emission Computed Tomography myocardial images yielded a concordance rate of 84.56% with Cohen’s kappa coefficient of 0.69. Conclusion: Substantial agreement and good concordance were found in normal and essentially normal ‘stress only’ and ‘rest stress protocols.